Fox-Body Mustang Five Lug Upgrade

Think it’s unnecessary to give Project Street Smart Windsor a five-lug upgrade? We give you five good reasons

Marc ChristAssociate Editor

October 18, 2011

There's no doubt that five-lug conversions are popular in the Fox-body community. We've established in the past that there's not much advantage to five lugs over four (on street cars like our Street Smart Windsor). So why upgrade? Well, here are five very good reasons.

5) Brake Upgrade

There's no better excuse to switch to a five-lug setup than a set of new binders. It improves the safety of your Mustang, especially when your hopped-up ride is relying on 30-year-old brake technology to bring it to a safe, controlled stop. What better way to keep you and your passengers safe than an old-fashioned brake kit?

For SSW, we turned to Baer Brakes, which offers a plethora of five-lug, Fox-body brake upgrade kits. There's everything from its Track4 front system (PN 4261276R; $1,395) and SS4 rear kits (PN4262270C; $1,195), to 14-inch, six-piston front kits for $3,195 (PN 4261070R). Depending on your particular budget, Baer has a kit for you. It will even supply brake fit templates, so you know exactly which wheels to pick.

We opted for the less expensive Track4 front kit and SS4 rear kit with Baer's new Veraslide technology. This allows the caliper to float, preventing pad slap.

4) Wheel Choices

This is probably most people's number one reason for doing a five-lug swap. As time passes further from 1993, fewer companies are catering to the four-lug community. Actually, we could only count about five street-wheel style choices available for the four-lug Foxes.

So you could either go with the same thing that everyone else is doing, or you can step up to five-lug and have an unlimited supply of wheel choices-so many that you'll drive yourself crazy over the decision. That's what happened to us when we decided to give SSW the upgrade.

After searching long and hard, and comparing photos we found on the web, we finally came across Billet Specialties' new Street Smart line (ironically enough). Though it offers seven different styles in this line, we opted for the Challenger.

Ranging from $310 to $525 each, these carved-from-billet, two-piece wheels give similarly priced cast wheels the long finger. To clear our new awesome (and safer) brakes, we went with 17x8 in the front and 17x9.5 in the rear. Backspace can be specified when you order, so make sure you get yours right before ordering.

And since you're upgrading from 15- or 16-inch wheels to 17s or larger, you have to buy new rubber as well. We went to TireRack.com for our new Firestone Firehawk Wide Oval Indy 500s, 235/45-17 in the front ($123 each) and 275/40-17 in the rear ($146 each). Though we did it the hard way (having the tires mounted and balanced ourselves), we recommend buying the wheels/tires combination directly from Tire Rack, so all you have to do is bolt them right on.

3) Rearend Upgrade

One of the biggest challenges of swapping to five-lug for most do-it-yourselfers is the axle swap. You have to remove the bolt and pin to release the C-clips, and you always risk that pin being jammed. So when life hands you lemons, you use it as an excuse to rebuild your rearend.

With the stock 28-spline axles out, what better time than then to do a gear swap, or say, a differential upgrade. Why not go ahead and upgrade to 31-spline axles? Mouse in hand, we went directly to FRPP's website for a set of 3.73 gears (PN M-4209-F373N; $179.95) and an axle bearing and seal kit (PN M-1225-B; $25). We also hit up Latemodel Restoration Supply for its five-lug conversion kit (PN LRS-4204B-K; $429.99), which includes 31-spline, five-lug axles; ten wheel studs; and a 31-spline, FRPP Traction-Lok differential.

2) Interchangeability

Let's face it-few of your friends still have the four-lug stock setup on their Fox-body (or they have a later-model Mustang), so if you need to bum a pair of drag radials, you're pretty much screwed. And when it comes time to upgrade your wheels or brakes later on, you don't have to change everything on the car to make the latest and greatest parts work.

1) Street Cred

Without a doubt, this is the best reason to do a five-lug upgrade. You can't have ôstreet smartsö on a set of 16-inch Ponies. You can't be a baller when you're rolling with drum brakes out back. And you probably won't be bragging about your stock diff with 2.73 gears and stock 28-spline axles. So if you want to kill five birds with one stone, check out what we did to the Street Smart Windsor.

In the clutch

Since we have yet to upgrade the stock clutch on SSW, we took this opportunity to install this Ram clutch. Since we recently replaced the flywheel (when we installed the engine), all we needed was the clutch, pressure plate, and release bearing.

We opted for Ram's Powergrip kit (PN RAM-98794; $299.99) from Latemodel Restoration Supply. Lamotta made quick work of the install, and it was back to work on the rest of the five-lug swap.